Optimizing the beam pattern of a forward-viewing ring-annular ultrasound array for intravascular imaging

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Cardiovascular Technology

Background:

• Intravascular ultrasound (IVUS) provides high-resolution cardiac images but requires conventional angioscopy for guidance.
• Current IVUS systems face limitations due to catheter guide wire constraints, preventing full-disk imaging apertures.
• Existing theoretical models for forward-viewing IVUS use impractical assumptions regarding transceiver arrangements and focusing strategies.

Purpose of the Study:

• To develop a practical array geometry and signal processing architecture for a real-time forward-viewing IVUS system.
• To enable integrated forward-viewing capabilities within cardiac catheters to reduce radiation exposure.
• To overcome limitations imposed by guide wire mounting on imaging aperture size.

Main Methods:

• Design of a novel array geometry for a forward-viewing IVUS catheter.
• Implementation of a synthetic reconstruction signal processing architecture.
• Utilizing 210 transceiver firings for 3-D image frame generation.

Main Results:

• Simulated results demonstrate side-lobe levels below -40 dB for on-axis imaging.
• Simulated results show side-lobe levels below -30 dB when steering to the edge of an 80-degree cone.
• The proposed design addresses practical array limitations and signal processing challenges.

Conclusions:

• The developed forward-viewing IVUS system design is practical and overcomes previous theoretical limitations.
• This system has the potential to significantly reduce radiation exposure in cardiac interventions.
• The synthetic reconstruction approach with the proposed array geometry achieves effective imaging performance.